@article{IM2_2015_79_5_a1,
     author = {S. V. Bolotin and V. V. Kozlov},
     title = {Calculus of variations in the large, existence of trajectories in a~domain with boundary, and {Whitney's} inverted pendulum problem},
     journal = {Izvestiya. Mathematics },
     pages = {894--901},
     publisher = {mathdoc},
     volume = {79},
     number = {5},
     year = {2015},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/IM2_2015_79_5_a1/}
}